A Technical Talk on A Technical Talk on C++ C++

bybySubhash.K.USubhash.K.U

@@P.E.S School of Engineering,P.E.S School of Engineering,

BangaloreBangalore

A Technical Talk on A Technical Talk on C++ C++

bybySubhash.K.USubhash.K.U

@@P.E.S School of Engineering,P.E.S School of Engineering,

BangaloreBangalore

About the speaker

Subhash.K.U currently works as Senior Software Engineer at Mascon Global Ltd, Bangalore. He is also a consultant for Motorola Solutions, Bangalore. He is the founder chairman and chief-facilitator at TeachGuru Foundation,Bangalore.

Special thanks to :

The Management, Principal and Head, Dept. of Computer Science

of P.E.S School of Engineering, , Bangalore, Karnataka, India.

Advantage of attending this seminar

• Primarily, my friendship • Learn and understand the

advantage of OOT• Learn basic concepts of OOP

A priori knowledge required ?

• Knowledge of basic C programming language

• Knowledge of compiling source files

Let us start with a Q ?

What is the major difference between C and C++ ?

• Inclusion of OO concepts to C++

• C is a POPL

• C++ is a OOPL

What is Procedure Oriented

Programming ?

• Try to solve a problem keeping procedures in mind

• Data insecurity is a major problem

Data Pollution !!!struct Library void Login( ){ { ……………….. Lib.Books = 7; //Dangerous

int Books ; } …………………};struct Library Lib;int main( ){ ……………………

Login( );………………………

}

What is Object Oriented

Programming ?• Programmers think in terms of

Objects

• Can model real world entities

• An object occupies space, has an identity and also has behaviour

How do you store integer numbers ?

– use “int a = 6; “

How do you store the real world entity “Book” while designing a Library Management System ?– use “User defined Objects“– No built in data type to store the real

world entity “Book” or “Pen” or “Employee”

How to create user-defined objects ?

– In C :• struct Book {

char name;int pages;double price;

} ;struct Book sku;sku.name = ‘s’; int a;sku.pages = 469; a = 6;sku.price = 335.00;

Disadvantage:• Cannot include related function within a structure. Or

cannot encapsulate.

In C++:

– struct Book { private: char name; state of an object

int pages; double price;

public: void GetBookDetails( ) behaviour of an

object {

//implementation details }

}; struct Book sku; occupies space and has an identity sku.name = ‘s’; sku.pages = 369;

sku.price = 335.00sku.GetBookDetails( );

OOP concepts in C++

• Encapsulation• Polymorphism• Inheritance• Abstraction

Encapsulation

• Shielding the data and functions that operate on that data together into one unit and protecting the data access from outside world is known as Encapsulation

Polymorphism• An entity in different forms• Example: int main( )

{int a[5] = { 0, 1, 2, 3, 4 };double b[5] = {2.2, 3.3, 5.5, 6.6, 2.0 };Add( a); // Add_int(a); in CAdd (b ); // Add_double(b); in C

}

InheritanceReusing the existing code by inheriting the characteristics of the

base class by a derived class.class Shape{ Draw( );};

class Square class Circle class Rectangle { { {

Draw( ); Draw( ); Draw( );}; }; };

Abstraction• Hiding implementation details.• Templates used to implement abstractionExample

int main( )

{int a[5] = { 4, 1, 2, 3, 0, 5 };char *name[3] = { “Subhash”, “Aishwarya”, “Yusuf

Pathan” };sort( a );sort( name );

}

A simple C++ program• #include <iostream> using namespace std; int main( )

{int a = 6;cout << a << endl;int b;cin >> b;cout << b;cout << “Subhash\n”;return 0;

}

#include <iostream> int main( ){

int a = 6;std::cout << a << std::endl;int b;std::cin >> b;std::cout << b;std::cout << “Subhash\n”;return 0;

}

How to access global data in C++ ?

#include <iostream>using namespace std;int a = 6;int main( ){

int a = 7;cout << a << endl;

}

• Using scope resolution operator [::]

#include <iostream>using namespace std;int a = 6;int main( ){

int a = 7;cout << ::a << endl;

}

A simple class and an its objects#include <iostream>using namespace std;class Example{

private:int a; //Data member

public:int b; // Data membervoid Set_Data( int x ) { a = x }; // member functionvoid Get_data( ) { cout << a << b << endl; } //member function

}; int main( ) {

Example e;e.a = 6; // result in compilation errore.b = 7; // legal statemente.Set_Data( 5 ); e,\e.Get_Data( )

}

Function Overloading#include <iostream>using namespace std;int Add( int x, int y ){

return ( x + y );} double Add( double x, double y ){

return ( x + y );}int main( ){

Add( 5, 6);Add( 5.5, 1.1 );

}

Inline Functions#include <iostream>using namespace std;inline Add( int x, int y ){

return (x + y );} int main( ){

int res = Add( 1, 2 ); // int res = x + y; }

Guess the output !!

#include <iostream>using namespace std;void Func( ){

cout << “void” << end;} int Func( ){

cout << “int” << endl;} int main( ){

Func( );}

Default Arguments#include <iostream>using namespace std;void Add( int, int, int = 1 );void Add( int x, int y, int z ){

cout << (x + y + z) << endl;} int main( ){

Add( 5, 6, 7); // CorrectAdd( 5, 6 ); // Correct Add(5); // Error

}

Guess the output#include <iostream>using namespace std;void Add( int, int = 9, int );void Add( int x, int y, int z ){

cout << (x + y + z) << endl;} int main( ){

Add( 5, 6, 7); // CorrectAdd( 5, 6 ); // Correct Add(5); // Error

}

Puzzle Test

Answer my puzzle and take away the prize !!!

Any Queries ?

Thank you !!!!

Contact me ?

• subhash.dgc@gmail.com (General)• subhash.writes@gmail.com (Technical)• Facebook (Subhash Ku)• Orkut (Subhash HMSIT)• Mobile: +91 9845456000